The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A168132 Numbers m = sum_(k=1...n) sigma(k) / k such that sum_(k=1...n) sigma(k) / k is integer for any k. 2
1, 2, 7, 9, 14, 52, 149, 213, 673, 1778, 3653, 6831, 9868, 570972, 2835107, 3613594, 47211979, 60418265, 99909506, 1701207282, 4587170542, 10955668024, 29031152874, 114018751785, 813149731047 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Numbers m = A024916(k) / k such that A024916(k) / k is integer for any k. If a(14) exist must be bigger than 82000.
Corresponding values of k, and sum_(k=1...n) sigma(k) are given in A056550 and A168133. [From Jaroslav Krizek, Nov 21 2009]
LINKS
EXAMPLE
Number a(3) = 7 is in sequence because A024916(8) / 8 = 56 / 8 = 7 is integer for k = 8.
CROSSREFS
Sequence in context: A341631 A102994 A226824 * A211280 A294863 A085544
KEYWORD
nonn
AUTHOR
Jaroslav Krizek, Nov 18 2009, Dec 04 2009
EXTENSIONS
a(14)-a(25) from Donovan Johnson, Jun 16 2011
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified June 17 18:36 EDT 2024. Contains 373463 sequences. (Running on oeis4.)